Biophysical landscape characterization of the upper pacal reservoir to support its sustainable management

Abstract

Pacal Reservoir provides irrigation to a total area of 16,688 hectares. Because of its critical importance for the downstream, activities in the upstream must be carefully controlled to maintain their functions. Information on the basic characteristics of landscape conditions is essential at the earliest stage of planning for sustainable land management. This paper aims to determine the characteristics of the upstream Pacal Reservoir and to analyze the areas that are likely suffering from degradation and contributing sediment. Thematic maps such as Area Function, Land Systems, Administration, Roads, and Rivers were used as well as Digital Elevation Model and Google Earth Imagery. The distribution of permanent vegetation, erosion hazard, the proper use of area function with actual land cover, and landslide hazard were investigated further. The spatial analysis indicates a moderate to very severe erosion hazard distributed in all land cover types. Deviations are in protected and production forest areas (2.15%) Land with a slope of >15% should be covered by permanent vegetation but used for seasonal covers (3.65%). Landslide hazards are low and moderate. Land rehabilitation is recommended mainly by maintaining/adding permanent vegetation in the degraded and potentially degraded areas.